Ionomer Compositions and Methods of Making and Using Same

ABSTRACT

A method comprising contacting at least one metal salt of an organic acid with at least one aromatic compound in a reaction zone under conditions suitable for the formation of a polymer, wherein the metal salt of an organic acid comprises a metal and at least one unsaturated organic acid moiety. A composition comprising polystyrene and a metal salt of cinnamic acid. An article made from a composition comprising polystyrene and a metal salt of cinnamic acid. A composition comprising polystyrene and a salt of a fatty acid. An article made from a composition comprising polystyrene and a salt of a fatty acid.

CROSS-REFERENCE TO RELATED APPLICATIONS

Not applicable.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

Not applicable.

REFERENCE TO A MICROFICHE APPENDIX

Not applicable.

BACKGROUND

1. Technical Field

This disclosure relates to polymeric compositions. More specifically,this disclosure relates to polymeric compositions for the preparation ofionomers.

2. Background

Ionomers are widely used in the manufacturing of a variety of end-usearticles ranging from medical devices to food containers. Ionomers thatare copolymers of styrene and methacrylic acid comprise some of the mostwidely used thermoplastic materials with a range of applicationsincluding disposable medical products, food packaging, tubing, andpoint-of-purchase displays.

Ionomers comprising aromatic moieties interconnected with ionic moietiesmay provide improved mechanical and/or physical properties when comparedto polymers lacking the ionic moieties. Of particular interest areionomers comprising aromatic moieties with a branched backbone, forexample ionomers comprising styrene. While styrenic based polymerstypically possess linear backbones, branched styrene-based polymers,which are generally termed branched aromatic ionomers, are desirable asthey typically exhibit higher melt strengths than linear congeners atsimilar melt flows. However, the application of these branched aromaticionomers can be limited by production difficulties (e.g., gel formationand reactor fouling) as well as end-use processing limitations. Thus, anongoing need exists for compositions and methodologies for theproduction of branched aromatic ionomer compositions having improvedproperties.

SUMMARY

Disclosed herein is a method comprising contacting at least one metalsalt of an organic acid with at least one aromatic compound in areaction zone under conditions suitable for the formation of a polymer,wherein the metal salt of an organic acid comprises a metal and at leastone unsaturated organic acid moiety.

Also disclosed herein is a composition comprising polystyrene and ametal salt of cinnamic acid. Further disclosed herein is an article madefrom a composition comprising polystyrene and a metal salt of cinnamicacid.

Also disclosed herein is a composition comprising polystyrene and a saltof a fatty acid. Further disclosed herein is an article made from acomposition comprising polystyrene and a salt of a fatty acid.

DETAILED DESCRIPTION

It should be understood at the outset that although an illustrativeimplementation of one or more embodiments are provided below, thedisclosed systems and/or methods may be implemented using any number oftechniques, whether currently known or in existence. The disclosureshould in no way be limited to the illustrative implementations,drawings, and techniques illustrated below, including the exemplarydesigns and implementations illustrated and described herein, but may bemodified within the scope of the appended claims along with their fullscope of equivalents.

Disclosed herein are methods of preparing aromatic ionomers. In anembodiment, the aromatic ionomer comprises one or more branched aromaticbased polymers having one or more ionic moieties. Compositionscomprising branched aromatic based polymers having one or more ionicmoieties are hereinafter termed aromatic ionomer compositions (AIC).

In an embodiment, a method of preparing an AIC comprises a copolymerformed by contacting a salt of an organic acid (i.e., a source compoundor precursor for the ionic moiety) with an aromatic compound andoptionally other components in a reaction zone under conditions suitablefor polymerization of an AIC. AICs of the type described herein maydisplay desirable physical and/or mechanical properties.

In an embodiment, one or more aromatic compounds are used as monomersfor the formation of the AIC and are included in same as repeatingunits. Aromatic compounds are chemical compounds that contain conjugatedplanar ring systems with delocalized pi electron clouds (i.e., aromaticgroups). Examples of aromatic compounds suitable for this disclosureinclude without limitation vinyl aromatic compounds such as styrene.

In an embodiment, the aromatic compound comprises a styrenic polymer(e.g., polystyrene) formed by polymerization of styrene, wherein thestyrenic polymer may be a styrenic homopolymer or a styrenic copolymer.Styrene which is also known as vinyl benzene, ethylenylbenzene, andphenylethene, and is an organic compound represented by the chemicalformula C₈H₈. Styrene is widely and commercially available and as usedherein the term styrene includes a variety of substituted styrenes(e.g., alpha-methyl styrene), ring-substituted styrenes (e.g.,t-butylstyrene, p-methylstyrene) as well as unsubstituted styrenes(e.g., vinyl toluene).

In an embodiment, the aromatic compound is present in the AIC in anamount of from 1.0 to 99.9% weight percent by total weight of the AIC,alternatively from 5 wt. % to 99 wt. %, alternatively from 10 wt. % to95 wt. %.

In an embodiment, one or more salts of one or more organic acids areused as monomers for the formation of the AIC, which become the ionicmoiety in the AIC. Salts of organic acids suitable for use in thisdisclosure include for example and without limitation metal salts oforganic acids. In an embodiment, the metal salt of an organic acid maycomprise a metal and at least one unsaturated organic acid moiety,alternatively a metal, at least one saturated organic acid moiety and atleast one unsaturated organic acid moiety (i.e., asymmetric salts).

In an embodiment, the metal salt of an organic acid comprises a metal.In some embodiments, the metal comprises Li, Na, K, Rb, Cs, Ca, Sr, Ba,Mg, Al, Zn, Mn, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Y, Zr , Nb, Mo,Tc, Ru, Rh, Pd, Ag, Cd, La, Hf, Ta, W, Re, Os, Ir, Pt, or combinationsthereof. Various factors may be considered in the selection of the metalto employ in the metal salts. For example, in determining a suitabletransition metal, the relative ease at which the metal's ligands aredisplaced to form metal salt upon reaction with the organic acid may beconsidered. In an embodiment, the metal comprises calcium, alternativelycadmium, alternatively zinc.

In an embodiment, the metal salt of an organic acid comprises an organicacid. Generally, organic acids are weak acids that do not dissociatecompletely in water but are soluble in organic solvents. In anembodiment, the organic acid comprises a vinyl group that can beincorporated into polystyrene as a random copolymer. Organic acidssuitable for use in this disclosure include for example and withoutlimitation cinnamic acid, benzoic acid, crotonic acid, itaconic acid,phenylcinnamic acid, α-methylcinnamic acid, fatty acid, such asundecylenic acid, or combinations thereof. In an embodiment, the organicacid comprises a styrene derivative, alternatively a styrene derivativecomprising a carboxylic acid moiety.

In an embodiment, the metal salt of an organic acid comprises zinccinnamate, calcium cinnamate, cadmium cinnamate, zinc undecylenate, zinccinnamate benzoate, zinc cinnamate acetate, or combinations thereof.

In an embodiment, the metal salt of an organic acid is present in theAIC in an amount of from 200 to 2000 parts per million (ppm) by totalweight of the AIC, alternatively from 500 to 1500 ppm, alternativelyfrom 750 to 1000 ppm.

In an embodiment, a process for production of the AIC comprisescontacting one or more aromatic compounds and one or more organic acidsalts under reaction conditions, and optionally in the presence of oneor more initiators, suitable for co-polymerization of the reactants toform the AIC. Suitable aromatic compounds and salts of organic acidshave been described previously herein.

In an embodiment, a process for the production of the AIC additionallycomprises contacting the composition with at least one initiator. Anyinitiator capable of free radical formation that facilitates thepolymerization of aromatic compound may be employed. Such initiatorsinclude by way of example and without limitation organic peroxides.Examples of organic peroxides useful for polymerization initiationinclude without limitation benzoyl peroxide, lauroyl peroxide, t-butylperoxybenzoate, 1,1-di-t-butylperoxy-2,4-di-t-butylcyclohexane, diacylperoxides, peroxydicarbonates, monoperoxycarbonates, peroxyketals,peroxyesters, dialkyl peroxides, hydroperoxides, or combinationsthereof. The selection of initiator and effective amount will depend onnumerous factors (e.g., temperature, reaction time) and can be chosen byone skilled in the art with the benefits of this disclosure to meet theneeds of the process. Polymerization initiators and their effectiveamounts have been described in U.S. Pat. Nos. 6,822,046; 4,861,127;5,559,162; 4,433,099; and 7,179,873, each of which is incorporated byreference herein in its entirety.

In an embodiment, a process for the production of the AIC uses heat asan initiator. In such embodiments, the composition may be heated to atemperature in the range of from 90° C. to 130° C., alternatively from100° C. to 120° C., alternatively from 105° C. to 115° C., andalternatively about 110° C.

In an embodiment, the polymerization reaction to form the AIC may becarried out in a solution or mass polymerization process. Masspolymerization, also known as bulk polymerization refers to thepolymerization of a monomer in the absence of any medium other than themonomer and a catalyst or polymerization initiator. Solutionpolymerization refers to a polymerization process in which the monomersand polymerization initiators are dissolved in a non-monomeric liquidsolvent at the beginning of the polymerization reaction. The liquid isusually also a solvent for the resulting polymer or copolymer.

The polymerization process can be either batch or continuous. In anembodiment, the polymerization reaction may be carried out using acontinuous production process in a polymerization apparatus comprising asingle reactor or a plurality of reactors. For example, the polymericcomposition can be prepared using an upflow reactor. Reactors andconditions for the production of a polymeric composition are disclosedin U.S. Pat. No. 4,777,210, which is incorporated by reference herein inits entirety.

The temperature ranges useful with the process of the present disclosurecan be selected to be consistent with the operational characteristics ofthe equipment used to perform the polymerization. In one embodiment, thetemperature range for the polymerization can be from 90° C. to 240° C.In another embodiment, the temperature range for the polymerization canbe from 100° C. to 180° C. In yet another embodiment, the polymerizationreaction may be carried out in a plurality of reactors with each reactorhaving an optimum temperature range. For example, the polymerizationreaction may be carried out in a reactor system employing a first andsecond polymerization reactors that are either continuously stirred tankreactors (CSTR) or plug-flow reactors. In an embodiment, apolymerization reactor for the production of an AIC of the typedisclosed herein comprising a plurality of reactors may have the firstreactor (e.g., a CSTR), also known as the prepolymerization reactor,operated in the temperature range of from 90° C. to 135° C. while thesecond reactor (e.g., CSTR or plug flow) may be operated in the range offrom 100° C. to 165° C.

The polymerized product effluent from the first reactor may be referredto herein as the prepolymer. When the prepolymer reaches the desiredconversion, it may be passed through a heating device into a secondreactor for further polymerization. The polymerized product effluentfrom the second reactor may be further processed as described in detailin the literature. Upon completion of the polymerization reaction, anAIC is recovered and subsequently processed, for example devolatized,pelletized, etc.

In an embodiment, the AIC may also comprise additives as deemednecessary to impart desired physical properties, such as, increasedgloss or color. Examples of additives include without limitationstabilizers, chain transfer agents, talc, antioxidants, UV stabilizers,lubricants, plasticizers, ultra-violet screening agents, oxidants,anti-oxidants, anti-static agents, ultraviolet light absorbents, fireretardants, processing oils, mold release agents, coloring agents,pigments/dyes, fillers, and/or other additives known to one skilled inthe art with the aid of this disclosure. The aforementioned additivesmay be used either singularly or in combination to form variousformulations of the composition. For example, stabilizers orstabilization agents may be employed to help protect the polymericcomposition from degradation due to exposure to excessive temperaturesand/or ultraviolet light. These additives may be included in amountseffective to impart the desired properties. Effective additive amountsand processes for inclusion of these additives to polymeric compositionsmay be determined by one skilled in the art with the aid of thisdisclosure. For example, one or more additives may be added afterrecovery of the AIC, for example during compounding such aspelletization. Alternatively or additionally to the inclusion of suchadditives in the aromatic polymer component of the AICs, such additivesmay be added during formation of the AIC or to one or more othercomponents of the AICs.

The resultant composition (i.e., AIC) may comprise branched aromaticionomers. The AICs display improved physical and/or mechanicalproperties when compared to an otherwise similar composition prepared inthe absence of the metal salts of organic acids of the type describedherein (e.g., cinnamate salts). However, other salts of the typepreviously described herein are also contemplated. Hereinafter, thedisclosure of properties is made in comparison to a polystyrenehomopolymer.

AICs prepared as described herein may comprise higher molecular weightcomponents. The weight-average molecular weight M_(w) is given byequation 1:

M_(w)=Σw_(x)M_(x)   (Equation 1)

where w_(x) is the weight-fraction of molecules whose weight is M_(x).The M_(w) is related to polymer strength properties such as tensilestrength and impact resistance. In an embodiment, the AICs of thisdisclosure have an M_(w) of from 200 kDaltons to 320 kDaltons,alternatively from 220 kDaltons to 300 kDaltons, alternatively from 240kDaltons to 280 kDaltons as determined by ASTM D-5296.

The AICs of this disclosure may be further characterized by a higherz-average molecular weight (M_(z)). The z-average molecular weight(M_(z)) is given by equation 2:

M_(z)Σw_(x)M_(x) ²/Σw_(x)M_(x)  (Equation 2)

where w_(x) is the weight-fraction of molecules whose weight is M_(x).M_(z) is related to polymer ductile properties such as elongation andflexibility. In an embodiment, the AICs of this disclosure have an M_(z)of equal to or greater than 380 Daltons, alternatively equal to orgreater than 400 Daltons, alternatively equal to or greater than 420Daltons as determined by ASTM D-5296.

In an embodiment, the addition of a comonomer of this disclosure to apolymer of styrene results in an AIC with a T_(g) from 90° C. to 130°C., alternatively from 100° C. to 120° C., alternatively from 105° C. to110° C., as determined in accordance with ASTM E1356-03 Standard TestMethod for Assignment of the Glass Transition Temperatures byDifferential Scanning calorimetry. The T_(g) is the temperature at whichamorphous polymers undergo a second order phase transition from arubbery, viscous amorphous solid to a brittle, glassy, amorphous solid.The level of reduction of the AIC's. T_(g) may depend on the amount ofcomonomer added.

In an embodiment, the AICs of this disclosure may have a lowered meltflow rate (MFR). For example, the AICs may have an MFR of from 1 g/10min. to 3 g/10 min., alternatively from 1.2 g/10 min. to 2.5 g/10 min.,alternatively from 1.5 g/10 min. to 2 g/10 min. The MFR may bedetermined using a dead-weight piston plastometer that extrudespolystyrene through an orifice of specified dimensions at a temperatureof 230° C. and a load of 2.16 kg in accordance with ASTM Standard TestMethod D-1238.

The AICs have a melt strength of from 0.01 Newton (N) to 0.06 N,alternatively from 0.015 N to 0.05 N, alternatively from 0.02 N to 0.04N. The melt strength refers to the strength of the plastic while in themolten state wherein the melt strength is measured by the hang time of a150 gram parison at 210° C. immediately following extrusion from a 0.1inch die gap.

The AICs of this disclosure may be converted to end-use articles by anysuitable method. In an embodiment, this conversion is a plastics shapingprocess such as blowmoulding, extrusion, injection blowmoulding,injection stretch blowmoulding, thermoforming, and the like.

The AICs may also be used to prepare foamed polymeric compositions. Forexample, the AIC may be mixed, melted, and foamed via extrusion, and themelted and foamed copolymer fed to a shaping device (e.g., mold, die,lay down bar, etc.). The foaming of the AIC may occur prior to, during,or subsequent to the shaping. Alternatively, the molten AIC may also beinjected into a mold, where the composition undergoes foaming and fillsthe mold to form a shaped end-use article.

The AIC may also be used in sheet applications. In an embodiment, theAIC is formed into a sheet, which is then subjected to furtherprocessing steps such as thermoforming to produce an end-use article.The AIC may also be used to prepare oriented styrenic polymercompositions. Oriented polystyrene (OPS) may be produced by forming orcasting a film and stretching the film in two directions. This allowsthe polystyrene molecules to align themselves, thus, improvingmechanical properties.

The AIC may also be used to manufacture molded articles. By having ahigher melt flow while retaining adequate physical properties, themolding cycle time may be reduced, thus allowing increased manufacturingproductivity. The AICs may be used in blends and alloys with polarpolymers such as polyethylene terephthalate and polycarbonate.

The AICs of this disclosure may be converted to end-use articles by anysuitable process and used to manufacture extruded articles, such asfoam, and extruded and/or oriented sheets or film. Examples of end usearticles into which the AICs of this disclosure may be formed includefood packaging, office supplies, plastic lumber, replacement lumber,patio decking, structural supports, laminate flooring compositions,polymeric foam substrate, decorative surfaces (i.e., crown molding,etc), weatherable outdoor materials, point-of-purchase signs anddisplays, housewares and consumer goods, building insulation, cosmeticspackaging, outdoor replacement materials, lids and containers (i.e., fordeli, fruit, candies and cookies), appliances, utensils, electronicparts, automotive parts, enclosures, protective head gear, reusablepaintballs, toys (e.g., LEGO bricks), musical instruments, golf clubheads, piping, business machines and telephone components, shower heads,door handles, faucet handles, wheel covers, automotive front grilles,and so forth.

EXAMPLES

The disclosure having been generally described, the following examplesare given as particular embodiments of the disclosure and to demonstratethe practice and advantages thereof. It is understood that the examplesare given by way of illustration and are not intended to limit thespecification or the claims to follow in any manner.

Example 1

Various AIC samples were prepared using the methodologies disclosedherein and their properties were compared to a commercially availablesample of polystyrene and to a sample comprising polystyrenemethylmethacrylate (PS-MMA). Sample 1 is a polystyrene homopolymer andwas prepared using a feed comprising crystal grade polystyrene PS-Xtalwhich is commercially available from Total Petrochemicals USA, Inc. and170 ppm of LUPEROX 233 (L-233) initiator. L-233 is ethyl3,3-d(t-butylperoxy)butyrate which is an organic peroxide initiatorcommercially available from ARKEMA. Sample 2 was a PS-MMA prepared usinga feed comprising approximately 20-30 ml of PS-Xtal and 800 ppm of zincdimethacrylate (ZnDMA) which is commercially available from Aldrich.

Samples 3 to 15 were prepared using approximately 20-30 ml of PS-Xtaland various zinc salts of organic acids at the amounts indicated inTable 1. All samples were batch polymerized at 131° C. in a reactorvessel.

The weight average molar mass (M_(w)), the z average molar mass (M_(z)),the glass transition temperature (Tg), the melt flow index (MFI) (alsotermed the melt flow rate), and the melt strength of Samples 1-15 weredetermined using the methodologies disclosed previously herein and theresults are tabulated in Table 1.

TABLE 1 Cross-linking Amount Mw Mz Melt monomer of Salt (kilo (kilo TgMFI Strength Sample system ppm Daltons) Daltons) ° C. g/10 min (N) 1 PSXtal ((L- n/a 240 377 107.4 2.43 0.024 233) 2 ZnDMA 800 273 414 107.81.36 0.064 (Aldrich) 3 ZnCin₂ 800 279 421 107.5 1.61 0.039 4 ZnCin₂ 1500274 410 109 1.64 0.037 5 CaCin₂ 1200 253 400 108.9 2.34 0.020 6 CaCin₂800 n/a n/a n/a 1.82 0.025 7 ZnCinAc 800 281 424 107.7 1.44 0.033 8ZnCinBz 400 271 410 108 1.95 0.028 9 ZnCinBz 800 264 408 108.6 2.170.031 10 CdCin₂ 975 n/a n/a n/a 1.70 0.028 11 ZnUn 200 279 423 108.71.71 0.030 12 ZnUn 400 278 426 109.3 1.91 n/a 13 ZnUn 800 278 419 1061.79 0.028 14 ZnUn 1200 278 418 105.9 1.81 n/a 15 ZnUn 2000 275 417106.3 1.94 0.024

Referring to Table 1, Zn(DMA) is zinc dimethacrylate, Zn(Cin)₂ is zinccinnamate, CaCin₂ is calcium cinnamate, ZnCinAc is zinc cinnamateacetate, ZnCinBz is zinc cinnamate benzoate, CdCin₂ is cadmiumcinnamate, ZnUn is zinc undecylenate. The value of Mz obtained for thezinc containing samples (Samples 3, 4, 7, 8, 9, 11-15) ranged from 408to 426, which are comparable to the Mz value for the PS-MMA using ZnDMA(Sample 2) of 414. Since the Mz values of PS-MMA are characteristic ofbranched polymers, the Mz values for the AIC of the disclosure (Samples3, 4, 7, 8, 9, and 11-15) suggests the samples have a branchedstructure. Additionally, the MFI of Samples 3-15 ranged from 1.44 to2.34, which falls within the range of values obtained for a PS-MMA of1.36 (Sample 2) and a polystyrene homopolymer of 2.43 (Sample 1).

The melt strength values for Samples 3-15, with the exception of Sample5 (CaCin₂), within the range of values obtained for a PS-MMA (Sample 2)and a polystyrene homopolymer (Sample 1). CaCin₂ may show melt strengthvalues outside the range due to the low solubility of CaCin₂ salt.

The asymmetric zinc salts of zinc cinnamate acetate and zinc cinnamatebenzoate (Samples 7-9) displayed a Mw that was comparable to thatobtained using zinc cinnamate (Samples 3-4). Further, a comparison ofSamples 5, 6, and 10, indicated that substitution of the zinc cation inthe AICs with cations of larger radii such as cadmium and smaller radiisuch as calcium resulted in lowered melt strengths.

Finally, the samples prepared using zinc undecylenate (Samples 11-15)displayed high Mw and Mz values without a substantial increase instiffness as reflected in high MFI values. These data suggest that thesamples prepared using zinc undecylenate had a substantial amount ofcrosslinking. These results for zinc undecylenate contradict data on thephysical properties of styrene ionomers with carboxylic acid moietyattached to alkyl chain spacer with variable length as describe byEisenberg A., Gauthier M., “Alkylated Styrene Ionomers with VariableLength Spacers. Physical Properties”, Macromol., 1990, 23, 2066-2074 andEisenberg A., Kim J. S., “Introduction to Ionomers”, Wiley Interscience,1998, New York, N.Y., each of which is incorporated by reference hereinit its entirety. The glass transition temperatures of the samplesprepared with the cinnamate salts were comparable to that of the controlsamples.

While embodiments have been shown and described, modifications thereofcan be made by one skilled in the art without departing from the spiritand teachings of the disclosure. The embodiments described herein areexemplary only, and are not intended to be limiting. Many variations andmodifications of the embodiments disclosed herein are possible and arewithin the scope of the disclosure. Where numerical ranges orlimitations are expressly stated, such express ranges or limitationsshould be understood to include iterative ranges or limitations of likemagnitude falling within the expressly stated ranges or limitations(e.g., from about 1 to about 10 includes, 2, 3, 4, etc.; greater than0.10 includes 0.11, 0.12, 0.13, etc.). For example, whenever a numericalrange with a lower limit, R_(L), and an upper limit, R_(U), isdisclosed, any number falling within the range is specificallydisclosed. In particular, the following numbers within the range arespecifically disclosed: R=R_(L)+k* (R_(U)−R_(L)), wherein k is avariable ranging from 1 percent to 100 percent with a 1 percentincrement, i.e., k is 1 percent, 2 percent, 3 percent, 4 percent, 5percent, . . . 50 percent, 51 percent, 52 percent, . . . , 95 percent,96 percent, 97 percent, 98 percent, 99 percent, or 100 percent.Moreover, any numerical range defined by two R numbers as defined in theabove is also specifically disclosed. Use of the term “optionally” withrespect to any element of a claim is intended to mean that the subjectelement is required, or alternatively, is not required. Bothalternatives are intended to be within the scope of the claim. Use ofbroader terms such as comprises, includes, having, etc. should beunderstood to provide support for narrower terms such as consisting of,consisting essentially of, comprised substantially of, etc.

Accordingly, the scope of protection is not limited by the descriptionset out above but is only limited by the claims which follow, that scopeincluding all equivalents of the subject matter of the claims. Each andevery claim is incorporated into the specification as an embodiment ofthe present disclosure. Thus, the claims are a further description andare an addition to the embodiments of the present disclosure. Thediscussion of a reference is not an admission that it is prior art tothe present disclosure, especially any reference that may have apublication date after the priority date of this application. Thedisclosures of all patents, patent applications, and publications citedherein are hereby incorporated by reference, to the extent that theyprovide exemplary, procedural, or other details supplementary to thoseset forth herein.

1-17. (canceled)
 18. A composition comprising a copolymer, wherein the copolymer is a copolymer of an aromatic compound and a salt of a fatty acid.
 19. The composition of claim 18, wherein the fatty acid comprises undecylenic acid.
 20. An article made from the composition of claim
 18. 21. The composition of claim 18, wherein the aromatic compound is present in an amount of from 1 weight percent to 99.9 weight percent based on a total weight of the composition, and wherein the salt of the fatty acid is present in an amount of from 200 ppm to 2000 ppm based on the total weight of the composition.
 22. The composition of claim 18, wherein the aromatic compound is a vinyl aromatic compound.
 23. The composition of claim 18, wherein aromatic compound is styrene.
 24. The composition of claim 18, wherein the salt of the fatty acid is a metal salt of the fatty acid.
 25. The composition of claim 24, wherein the metal of the metal salt of the fatty acid comprises Li, Na, K, Rb, Cs, Ca, Sr, Ba, Mg, Al, Zn, Mn, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Y, Zr, Nb, Mo, Tc, Ru, Rh, Pd, Ag, Cd, La, Hf, Ta, W, Re, Os, Ir, Pt, or combinations thereof.
 26. The composition of claim 18, wherein the copolymer has a weight-average molecular weight of from 200 kilo Daltons to 320 kilo Daltons, as determined by ASTM D-5296.
 27. The composition of claim 18, wherein the copolymer has a z-average molecular weight of equal to or greater than 380 kilo Daltons, as determined by ASTM D-5296.
 28. The composition of claim 18, wherein the copolymer has a glass transition temperature of from 90° C. to 130° C., as determined by Differential Scanning calorimetry in accordance with ASTM E1356-03.
 29. The composition of claim 18, wherein the copolymer has a melt flow rate of from 1 g/10 min. to 3 g/10 min, as determined by ASTM D-1238 at 230° C. and a load of 2.16 kg.
 30. The composition of claim 18, wherein the copolymer has a melt strength of from 0.01 Newton (N) to 0.06 N.
 31. The composition of claim 18, wherein the composition comprises one or more polar polymers.
 32. The composition of claim 31, wherein the polar polymers comprise polyethylene terephthalate and polycarbonate.
 33. The article of claim 20, wherein the article is a blowmoulded article, an extruded article, an injection blowmoulded article, an injection stretch blowmoulded article, or a thermoformed article.
 34. The article of claim 20, wherein the article is a foamed article.
 35. The article of claim 20, wherein the article is a cast film or an oriented film.
 36. A composition comprising a copolymer, wherein the copolymer is a copolymer of an aromatic compound and a metal salt of an organic acid, wherein the metal salt of the organic acid has at least one unsaturated organic acid moiety.
 37. The composition of claim 36, wherein the organic acid comprises benzoic acid, crotonic acid, itaconic acid, phenylcinnamic acid, α-methylcinnamic acid, or combinations thereof.
 38. The composition of claim 36, wherein the organic acid comprises a styrene derivative.
 39. The composition of claim 38, wherein the styrene derivative comprises a carboxylic acid moiety.
 40. The composition of claim 36, wherein the aromatic compound is present in an amount of from 1 weight percent to 99.9 weight percent based on a total weight of the composition, and wherein the metal salt of the organic acid is present in an amount of from 200 ppm to 2000 ppm based on the total weight of the composition.
 41. An article made from the composition of claim
 36. 